Veterinary clinical pathology最新文献

Background: Biochemistry analyzers, which utilize indirect potentiometry, are used to determine serum electrolyte concentrations in dogs. Artifactual increases or decreases in these electrolyte concentrations can be caused by alterations in the serum water fraction (SWF). Severe hypo- and hyperproteinemia cause changes in SWF, which can then result in incorrectly reported serum sodium concentrations.

Objectives: The goals of this study were to determine an average actual SWF (SWF_ACTUAL) in dogs and establish formulae to correct serum sodium concentration measured by indirect potentiometry in hypo- and hyperproteinemic patients.

Methods: Serum samples from 115 canine patients were analyzed for electrolytes measured by both indirect and direct potentiometry. Total protein, albumin, triglycerides, and cholesterol were also determined. Each serum sample was then lyophilized to determine SWF_ACTUAL. A canine-specific formula to estimate SWF (SWF_EST-CAN) was developed using a multivariable linear model and compared with the human-estimated formula (SWF_EST-HUM).

Results: The mean SWF_ACTUAL in this population of dogs was 92.7%, which was significantly different (p < .0001) than the mean (95.1%) calculated using SWF_EST-HUM. The formula derived from SWF_EST-CAN recapitulated SWF_ACTUAL more accurately than SWF_EST-HUM. Based on a slope closer to 1.0, the corrected sodium concentrations calculated using the canine formula correlated marginally better with the serum sodium measured by direct potentiometry than those calculated using the human formula.

Conclusions: Applications of correction formulae are expected to limit the misinterpretation of electrolyte data from indirect potentiometry when altered SWF occurs. A case example of the potential utility of these correction formulae is presented.

Background: Total thyroxine (TT4) measurement is used to assess thyroid status in cats.

Objectives: The aim of the prospective study was to evaluate the analytical performance of the point-of-care analyzer (POCA) Immuno AU10V using the v-T4 test kit for feline TT4 measurement. Additionally, method comparison with a benchtop analyzer (IMMULITE 2000) was done.

Methods: Validation included linearity, inter- and intra-assay precision, precision near the lower limit of quantification (LloQ), and interference testing for hemoglobin, lipid, and bilirubin. Correlation and bias were assessed.

Results: Linearity was given within the dynamic range. Coefficients of variation (CV) were ≤4% near the LloQ as well as for intra-and inter-assay precision. No interference was observed for lipid and bilirubin, while hemoglobin caused a negative bias of 28%. Method comparison included 74 samples within three TT4 concentration ranges (0.5-3.7, >3.7-5.13, >5.13-8 μg/dL). Correlation between POCA and reference method was excellent (r_s = 0.95) with a slight proportional bias of 4.5%. TE_obs was between 7.0% and 9.8%. Despite substantial agreement, discordant results on thyroid status occurred in 15% of samples.

Conclusions: The analytical performance of the POCA was excellent, as was its correlation with the reference method. Except for the interferent effect of hemoglobin, the TE_obs was a for all analyses. Analysis of severely hemolytic samples is not advised. However, the relatively small dynamic range of the POCA precludes quantitative analysis of samples with TT4 >8 μg/dL, and de novo reference intervals need to be established.

Background: As obligate scavengers, New World vultures (Cathartiformes: Cathartidae) play a key role in carcass removal and disease control. Associated with this ecosystem service, vultures are exposed to the consumption of harmful substances such as poisons, heavy metals, antibiotics, or non-steroidal anti-inflammatory drugs. Monitoring the health status of vulture populations is a priority and an important conservation strategy, and hematologic analysis is a practical and effective method that can be useful for this purpose.

Objectives: Report hematologic reference intervals in free-living King vultures (Sarcoramphus papa), one of the least studied New World vulture species.

Methods: Red blood cell concentration, packed cell volume, hemoglobin (Hb) concentration, MCV, MCH, MCHC, WBC concentration, differential count and absolute WBC concentration, heterophil to lymphocyte ratio, and total protein concentration were determined. We used a non-parametric method to calculate the reference intervals. In addition, we compared our results with the hematologic measurands reported for the Black vulture (Coragyps atratus), the Andean condor (Vultur gryphus) and the California condor (Gymnogyps californianus).

Results: With the exception of Hb, monocyte, basophil, and eosinophil concentrations, the mean hematologic measurands observed in the King vulture were similar to those recorded for the other New World vulture species, and the heterophil to lymphocyte ratio was lower in the King vulture compared to the Black vulture.

Conclusions: In this study, we have reported for the first time the hematologic reference intervals in a free-living population of King vultures in Costa Rica. Future research should consider comparison among free-living New World vulture species.

MicroRNAs (miRNAs or miRs) are small, non-coding RNAs that play a crucial role in gene regulation, making them potential biomarkers for various diseases. In the field of veterinary medicine, there is a growing interest in exploring the diagnostic and therapeutic potential of miRNAs in kidney diseases affecting dogs and cats. This review focuses on the use of urinary miRNAs as biomarkers for chronic kidney disease (CKD) in these companion animals. We introduce miRNAs, their biogenesis, and their presence in biofluids, particularly within exosomes, and discuss studies investigating miRNAs in kidney tissue and urine. We acknowledge the challenges associated with miRNA studies, including preanalytical factors such as biological variation, sample collection/processing, storage conditions, and experimental design. We highlight the importance of technical considerations, such as sample pooling, sequencing depth, multiplexing, and the various steps of the miRNA experimental workflow. Furthermore, we discuss RNA isolation methods, small RNA sequencing data analysis, and the use of quantitative reverse transcription PCR (qRT-PCR) and droplet digital PCR for verification. We emphasize the importance of internal controls, spike-ins, and normalization methods to minimize technical variation and ensure reliable results in qRT-PCR analysis. This review concludes that while urinary miRNAs hold promise as non-invasive biomarkers for CKD in dogs and cats, addressing the challenges and standardization of protocols is vital for the successful translation of this research into clinical practice.

Artificial intelligence (AI) is emerging as a valuable diagnostic tool in veterinary medicine, offering affordable and accessible tests that can match or even exceed the performance of medical professionals in similar tasks. Despite the promising outcomes of using AI systems (AIS) as highly accurate diagnostic tools, the field of quality assurance in AIS is still in its early stages. Our Part I manuscript focused on the development and technical validation of an AIS. In Part II, we explore the next step in development: external validation (i.e., in silico testing). This phase is a critical quality assurance component for any AIS intended for medical use, ensuring that high-quality diagnostics remain the standard in veterinary medicine. The quality assurance process for evaluating an AIS involves rigorous: (1) investigation of sources of bias, (2) application of calibration methods and prediction of uncertainty, (3) implementation of safety monitoring systems, and (4) assessment of repeatability and robustness. Testing with unseen data is an essential part of in silico testing, as it ensures the accuracy and precision of the AIS output.